title: Molecular systematics of Dendrobium (Orchidaceae, Dendrobieae) from mainland Asia based on plastid and nuclear sequences.
abstract: Dendrobium is one of the three largest genera and presents some of the most intricate taxonomic problems in the family Orchidaceae. Based on five DNA markers and a broad sampling of Dendrobium and its relatives from mainland Asia (109 species), our results indicate that mainland Asia Dendrobium is divided into eight clades (with two unplaced species) that form polytomies along the spine of the cladogram. Both Dendrobium and Epigeneium are well supported as monophyletic, whereas sect. Dendrobium, sect. Densiflora, sect. Breviflores, sect. Holochrysa, are paraphyletic/polyphyletic. Many ignored phylogenetic relationships, such as the one of major clades formed by D. jenkinsii and D. lindleyi (two members of sect. Densiflora), the Aphyllum group, the Devonianum group, the Catenatum group, the Crepidatum group, and the Dendrobium moniliforme complex are well supported by both molecular and morphological evidence. Based on our data, we propose to broaden sect. Dendrobium to include sect. Stuposa, sect. Breviflores, and sect. Holochrysa and to establish a new section to accommodate D. jenkinsii and D. lindleyi. Our results indicated that it is preferable to use a broad generic concept of Dendrobium and to pursue an improved infrageneric classification at sectional level, taking into account both morphology and current molecular findings.
authors.affiliation: State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 10093, China. Electronic address: xiangxg2010@ibcas.ac.cn.
authors.forename: Xiao-Guo
authors.initials: XG
authors.lastname: Xiang
authors.forename: André
authors.initials: A
authors.lastname: Schuiteman
authors.forename: De-Zhu
authors.initials: DZ
authors.lastname: Li
authors.forename: Wei-Chang
authors.initials: WC
authors.lastname: Huang
authors.forename: Shih-Wen
authors.initials: SW
authors.lastname: Chung
authors.forename: Jian-Wu
authors.initials: JW
authors.lastname: Li
authors.forename: Hai-Lang
authors.initials: HL
authors.lastname: Zhou
authors.forename: Wei-Tao
authors.initials: WT
authors.lastname: Jin
authors.forename: Yang-Jun
authors.initials: YJ
authors.lastname: Lai
authors.forename: Zhen-Yu
authors.initials: ZY
authors.lastname: Li
authors.forename: Xiao-Hua
authors.initials: XH
authors.lastname: Jin
mesh_terms: D001208:Asia; D001499:Bayes Theorem; D002467:Cell Nucleus / Q000235:genetics; D018742:DNA, Chloroplast / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D031667:Dendrobium / Q000033:anatomy & histology / Q000145:classification* / Q000235:genetics; D005819:Genetic Markers; D008957:Models, Genetic; D010802:Phylogeny; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
chemical_list: D018742:DNA, Chloroplast; D018744:DNA, Plant; D005819:Genetic Markers
keywords: Dendrobium; Mainland Asia; Molecular systematics; Sect. Dendrobium; Sect. Densiflora; Sect. Holochrysa